Initial concentrations are the same at equilibrium?

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Tai Metzger 3K
Posts: 103
Joined: Sat Aug 24, 2019 12:17 am

Initial concentrations are the same at equilibrium?

Postby Tai Metzger 3K » Wed Jan 22, 2020 12:40 pm

I was doing some practice problems and for a couple I found that x was found to be so small that the concentrations for the reactants were the same at equilibrium as they were initially. Is this possible and/or common? Thanks!

KeyaV1C
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Joined: Sat Aug 17, 2019 12:17 am
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Re: Initial concentrations are the same at equilibrium?

Postby KeyaV1C » Wed Jan 22, 2020 1:32 pm

When K is really small, the value of x tends to be really small as well, barely changing the concentration of the reactants.

Marni Kahn 1A
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Re: Initial concentrations are the same at equilibrium?

Postby Marni Kahn 1A » Wed Jan 22, 2020 2:10 pm

This is seen quite often because we do a lot of examples with an infinitesimally small value of Ka

Morgan Carrington 2H
Posts: 54
Joined: Wed Nov 14, 2018 12:22 am

Re: Initial concentrations are the same at equilibrium?

Postby Morgan Carrington 2H » Wed Jan 22, 2020 2:27 pm

It is possible and commonly seen when doing acid and/or base equilibrium, but I would warn to be careful getting comfortable doing it because there are times when you can't use that rule.


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